Saba’s shores featured in Sea & Learn

Over 75 people turned out at El Momo Cottages on Tuesday for Jennifer Rahn’s “Where’s the Beach?” presentation, providing an accessible scientific understanding of Saba’s elusive “wandering beach” phenomenon. Cartographer, coastal geo-morphologist and dive master Rahn is Director of the Environmental Studies Scholars Programme at Samford University in Birmingham, Alabama, bringing student groups to Saba each January, for intensive student- participation research.

A regular long-stay visitor since 1991, Rahn has been conducting research on Saba’s coastline for the last four years, trying to establish baseline topographic and bathymetric information. She has gained a local reputation for her costal research projects, especially her quarterly survey of Tent Reef Beach. Recently, her report was submitted to the island government by Saba Conservation Foundation, calling attention to the threat posed by construction debris and soil deposited in the area from various construction sites. The deposits allegedly pose high risks for nearby marine life and some of the most popular local dive sites.

Rahn explained the lowtech method she developed in creating and monitoring beach profiles and the community support she received over the years. She also spoke of beach nourishment and the attempt to create a white sand beach at Cove Bay with sand donated from St. Maarten. Beach nourishment is a longstanding researched activity in the United States, where the first such experiment occurred in the 1920s. Rahn showed photos of the additional sand dumped this month at Cove Bay. While beach nourishment is rare in the Caribbean, almost all tourist beaches in Northern America are actively managed with multi-million investments, without a guaranteed longlasting outcome.

Asked if Cove Bay beach nourishment posed any ecological threat, Rahn confirmed that the size of the deposited sand is appropriate and that the scale of the project poses no threat to any nearby reef. Instead, she suggested Well’s Bay as a potential good site for larger beach nourishment, explaining why the sand there would have to be pumped from offshore. Data collected over the years suggest that Well’s Bay is unlikely to be naturally resupplied with sand. The sand had been carried beyond the “depth of closure” and waves can no longer return it ashore. She also explained the erosion process of volcanic sediment and cliffs at Well’s Bay.

Source: “The Daily Herald” 2012-10-15